Balance testing



Dec. 16, 1947. P. DAVEY BALANCE TESTING Filed April 14, 1943 4Sheets-Sheet l INVENTOR 22Ln ATT ORNEY P. DAVEY Dec. 16, 1947.

BALANCE TESTING Filed April 1 1, 1943 4 Sheets-Sheet 2 VIII/4' INVENTORAL-M E M g ATTORNEY Dec. 16, 1947, DAVEY 2,432,730

' BALANCE TESTING v V v Filed April 14, 1943 4 Sheets-Sheet 3 INVENTORATTORNEY Dec. 16, 1947. P. DAVEY BALANCE TESTING Filed April 14, 1943 4Sheets-Shqet 4 INVENTOR a ATTORN EY Patented Dec. 16, 1947 UNITE ED STATES PAT E N T O F F ICE BALANGE TESTING Beter' Davey,nWhite Plains, N. Y.

Application April"14, 1943, SerialNo; 483,051

2. Claims: 1

This invention relates to" dynamic balancing; particularly to means 'forobtaining the ampli-- tudeof vibration and-apparent positionof the 1111-balancing-'mass in an unbalanced rotatingbody:

A principal objector this invention is to-providemeans-bywhich a personwhile visually observing; as by a-vibrometer, the indication of theamplitude-of vibration caused" by an unbalanced rotating body, and evenwhileholdingthe -vh brometer, may, himself, make adjustments, whereby hemaybe assured that the apparent position of the unbalancing mass is inthe plane in which the amplitudeis'being measured, that is,

generally stated, determine-therelation of the vibrating motionproduced. by the unb-alancing mass to the position of-theunbalancing-mass in therotating body:

A further object of; the: invention is the provision of a circuitcontroller adapted to be driven by a rotating body and so constructedthat it may be operated from a remote point by asimple manipulation, toproduce a circuit-change at any desired angular position of a-rotatingbody with reference to a given plane through the body.

A further object of the invention-is'to provide means forcontrolling-stroboscopic lamps so that they may be flashed at anydesired point in the cycle of movement of a movable-body and to enablevariation of that point bya simple manual motion, if necessary, whileactually manually holding a,vibrationexhibitingdevicein place to exhibitvibration caused bya' moving body;

Other objects. and advantages will appearas the description of aparticular. means illustrative of the invention progresses, andthe novelfeatures will be particularlypointed out in the appended claims.

In describing the invention in detail, and the particular meansillustrative of the invention, reference willbe-hadto'the accompanyingdrawings and the several views thereon, in which, like characters ofreference designate like parts throughout the several views, andinwhich:

Fig; 1 isa schematicview illustrating the general disposition ofthevarious pieces-of apparatus which are employedimorder to; obtaintheamplitude of vibration caused by anxunbalanced rotatingbody andthe-'apparent'position of the unbalance; Fig:.2;is a-top plan ,viewofia' remote, manually adjustable, rotatingbodydriven-circuit'controller used in connection with my invention; Fig.- 3is aviewbfthedeviee; as shown by Fig; 2, asseen from the right handgsidewith someparts in section and other parts removedinorder to moreclearlyshowthe construction;,Fi'g .-4 is a; view of the device,,as shown by,Fig.2; viewed, from the left-hand side thereof; Fig. 5'13 atop planview,

similar to Fig, 2', but with the'upper'portion ofthe case cut away in"ordertojimore clearly; illustrate.

theinterior construction; Fig; 6 is a cross section of the device ofFig. 5"; Fig. dis a cross sectional view of -the device, asshown in Fig.5'; on the plane: indicated by theline VIIIVIII'.ofFig: 5; viewedin-thedirectionof the arrowsat the endsof the line: Fig; 9 is afragmentary detail viewillustrating the construction and operation of apushbutton-switch included in the device, Fig; 5; 10"is a: fragmentaryenlarged viewshowing the construotionof a manually operable circuitcon.-

troller associated with a vibrometer used lin my:

invention. Fig. 11 Ba fragmentary top planview,

of the device as shown in Fig. 10; Fig. 12 is a cross;

sectional view on the plane' indicated by thezline XII-XII- of Fig. 11,viewed in the directiononthe arrows at. the ends of the line. Fig.l3-"is a cross sectional view on the plane indicatedbyth'e lineXIII'XIII of Fig. 12 viewed in the direction of thearrowsat the ends-ofthe line; Fig; 14 is=a:

schematic view illustrating the wiring connec-:

tions for associating the various-piecesof'apparatus usedin carrying outmy invention.

The desirability and even thenecessity'for removing' unbalance inrotating bodies is becoming- This is particularly recognized more andmore. true in the case of bodies rotated at relatively high speed!Rotating bodies which are in unbalance i notonly cause a disagreeablevibratiombuttalso. wear outmore quickly and if the unbalance isone whichis increasing; may suddenly destroy-themselves. I

Many machines have been devised for ascertaining thedata-necessary'forbalancing machines:

and-parts ofmachines in the shop or at the bench. These balancingmachines may be so constructed that all'parts are in such'positionsandso supported that they may be manipulatedreadily by one person.

A-more di-fficult problem arises in ascertaining thedata necessary forbalancing machines-after they have been manufactured and installed invarious situations and where it is quite impossible to usesomeone of thewell known shop-or bench balancing machines for balancing. It isin suchsituations, that is, balancing in the field, to which my means areparticularly adapted.

The general arrangement of mymeans is best shown in' Fig. 1. Forillustration, in Fig. 1, there has-been shown a rotatable body l3-mounted on a shaft- M which is supported, at one end, in a box l5: Thebody I3 is assumed, when rotated,

; to cause a vibratiominthe horizontalplane, of-

the box 15 dueto unbalance in the body l3. In

order to correct the unbalance, both itsvalue and its-position must beknown.

In; order to ascertain the value of unbalance,

f" is -I1ecessary to measure-the amplitude of the vibration caused bythat unbalance. I make use of a vibrometer. The preferred vibrometer I6is of my'invention, and is shown, described, and claimed, in UnitedStates Patent No, 1,949,603 granted March 6, 1934. This vibrometer is ofa construction such that when a movable point l1 thereof is positionedagainst a box, such as l5, vibration of the box is transmitted to thepoint I! and so to internal mechanism of the vibrometer and theamplitude of the vibration in fractions of an inch is indicated on thedial 8 by the movement of a line of white light, all as described in thesaid patent.

In order to obtain the apparent position of the unbalancing mass in thebody I3, it is necessary, for simplicity in calculation, to ascertainthe exact point in the periphery of the body l3, which lies in the planein which the amplitude of vibration is being measured, which is,generally, the exact point of the body lying in a horizontal planepassing through the longitudinal axis of the rotating body, in thepresent case, through the longitudinal axis of the shaft I4, at themoment when that point is the high-spot, or apparent position of theunbalancing mass, or the so-called phase angle of unbalance. I provide ameans for indicating when the high-spot is in the plane of the vibrationbeing measured and also means for visually ascertaining what particularpart of the rotating body is at that point.

The means used by me comprise a rotating body driven circuit controller2|, a discharge lamp, neon lamp, or stroboscopic lamp 23 and anadjustable discharge, neon, or stroboscopic lamp beam or band l9,together with the necessary electrical current supply and transformerdevices. The angular position referred to any plane, say the horizontalplane through the longitudinal axis of the shaft I4, at which a circuitis changed by the rotating body driven circuit controller 2|, determinesthe position of neon beam l9. When circuit controller 2| changes itscircuit at the moment the amplitude of vibration, as indicated by thevibrometer H5, is a maximum, the neon beam I9 is at the extreme right,as shown in Fig. 1. At that moment the neon lamp 23, also being, infact, a stroboscope, is also energized momentarily. At that time thehighspot or apparent position of the unbalancing mass is in the samehorizontal plane as the longitudinal axis of the shaft I4, that is,opposite the arrow 25, the neon lamp 23 illuminating that point willenable the operator to see that the point 6 on the body I3 is the highpoint; of the body l3.

The principles and means of the foregoing descriptions are all in theprior art and are illustrated and described in my before mentionedpatent.

In accordance with prior art, the operator of the vibrometer I 6 wouldrequire the assistance of another person to hold the rotary body drivencircuit controller 2| against the end of shaft M. It would be mostunlikely that the circuit controller 2| would change the circuit at theproper instant so that it would be necessary to adjust the circuitcontroller by the person holding the circuit controller, so that thedesired conditions would obtain. Directions for adjusting the circuitcontroller 2| would have to come from the operator of the vibrometer Hi.It has been found in practice that such a method is unsatisfactory, tosay the least. This arises from the fact that the conditions under whichthe devices are used are often and quite generally unsatisfactory, b?-

cause either the holder of the circuit controller 2| is inexperienced ordoes not quite appreciate the directions for adjustment given to him, orthe extreme noises, generally encountered, prevent the easy transmissionof instructions from the holder of the vibrometer to the holder of thecircuit controller 2|. In fact, in many situations, the holder of thevibrometer l6 and the holder of the controller 2| are separated by aconsiderable distance which further adds to the difficulty ofcommunication.

In order to remedy the difficulties of the prior means, I have provideda manually operable switch finger piece 24 on the vibrometer l6 and haveso constructed the controller 2|, that by means of that switch and anelectrical current and electrical conductors between the switch onvibrometer l6 and the circuit controller 2|, I may, even whileconstantly reading the amplitude of vibration, adjust the circuitcontroller 2| to the desired position so that the desired conditions areattained, so that the circuit controller 2| may be held in operativeposition by a person or by an inanimate device.

The manually adjustable, rotating body driven circuit controller 2| hasan enclosing casing 25. This enclosing casing includes an enclosingpartially truncated cylindrical top 26, best shown in Fig. 8. Thecasing, when viewed from the righthand side as drawn in Fig. 5, isprovided with an opening 26 as best shown in Fig. 3. This opening isclosed by a suitably formed plate 21 secured in any suitable orappropriate manner as by means of screws 28, 29, 30, and 3| screwthreaded into threaded cavities 32, 33, 34, and 35, respectively in thecasing 25.

The left-hand side of the casing, as drawn in Fig. 5, also has anopening which is closed by a cover 36 attached in any suitable orappropriate manner, as by screws 31, 38, 39 threaded into screw cavities40, 4|, 42, respectively, of the casing 25.

The casing 25, on the right-hand side, as viewed in Fig. 5, is providedwith a protuberance or bearing support 43 substantially in the form of ahollow cylinder. Within this protuberance 43 are positioned ballbearings 44 and 45. These ball bearings support the actuating shaft 46.

The actuating shaft 46 is provided with a conical end or point 48adapted to bear in a conical depression 4'! of the shaft M of a rotatingbody, and thereby be driven. The shaft 46 is provided with suitablecollars as 49 and 58, to maintain it in proper position longitudinally.The collar 50 may be adjusted longitudinally of shaft 46 and held inadjusted position by means of a set screw 5|. A spring washer 52 ispreferably positioned between the ball bearings 44 and the collar 56, inorder to exert a constant spring pressure thereagainst in order that thepressure of the conical point 48 against the shaft l4 will not result increating undue friction. The far end of the shaft 46 is provided with aball bearing 53, the inner race 54 of which is firmly attached to shaft46 and the outer race 55 of which is firmly attached to an adjustablecontacts carrying disc 56 made of any suitable or appropriate material.This construction, while supporting the disc 56, allows it to be rotatedindependently of the shaft 46. The shaft 46 also carries the cams 5'!and 58.

The contact carrying disc 56 supports the cam actuated electricalcircuit make and break devices. These include an oscillatable plate 58*,the broad surface of which bears directly against the disc 58, as bestshown inl 'ig. 8. I'Ihis Dmitlatable plate is securedin oscillatedposition by a screw 59, screw threaded directly into the "disc 56 withan interposed Washer '58. Whenlthis screw 59 is driven home the plate58' is heldin adjusted or oscillated position. If the plate is not inthe proper position, it is oscillated to the proper position byloosening the screw 59 and then rotating, as by a screw driver in slot61, the screw 62, screw threaded into the disc 56 and bearing the camhead 63 positioned in the cam slot 64 of the osciilatable plate 58. Bymeans of this cam headed screw 62,- proper adjustment of plate 58 may beobtained.

Plate 58 beats a stud B5 and around this stud is an insulatingsleevefifil. Surrounding andsupported by the insulating sleeve 66 is themovable contact arm 61, bearing at its extreme end the electricalcontact 58 arranged and positioned to cooperate with the electricalcontact '69 posttioned on the right angle bent portion of theoscillatable plate 58*. The contact arm 51 is spring pressed to causeits. contact 68 to make contact with 69, by means of the somewhat U-shaped spring H which is supported at one end by the post t2 mounted onthe disc 56. The other end 13 is attached to the movable contact arm 61,so as to cause that arm to be liitedupwardly, as viewed in Fig. 8,rotating on stud B5. The end 13 also bears the cam engaging project'-tion 74, so that when cams-51 and 58 are rotated, they contact member 14and separate movable contacts 68 and 69. a l

The separation of contacts 68 and 69' will occur at an instant in therotation of the shaft 46, that is, ata definite angular position of thatshaft with reference to a given plane depending upon the position ofdisc 56 rotativelyaboutshait 46. From the hereinbefore givendescription, it will be understood that it is necessary to cause thecircuit change to occur at a particular angular position of the rotatingbody which drives shaft 46. To accomplish this, the disc 55 nmst berotated to difierent angular positions about the shaft 46, The directdriving means for ac complishing this adjustment is the belt I5 passingaround disc 56 and seated in the roove 16, The belt '15 also passesaround the drivingpullcy Tl mounted on shaft 18.

In order to suitably rotate shaft 18, and so r pulley H, and so disc 56to a new and desired position, applicant'mounts a'toothed wheel it onthe shaft 18, best shown in Fig. 3. The teeth 80' of this wheel areengaged by a driving detent 31 mounted on an arm 82. The arm 82 isoscillat ably mounted on shaft 18 and is held in one direction by thetension spring 83. The arm tt bears an outstanding drivingpin 84'. Thisdriving pin '84 lies in a groove 85 forming part of the core andarmature of electr c-magnet or solenoid 86. In Fig. 3, the core 8l andthe armature 88 are shown in the outer or unattracted position" and thelimit of outward movement is controlled by the stop pin 89, passingscrew threadedly through the wall of the case 25 and'held adjustedposition by the lock nut 91]. When the solenoid 8B is suitablyenergized, the armature 83 and the core 8! move to the right, asviewedin Fig. 3, carrying the groove 85 to the right, and so carryingthe driving pin 84 to the rightywhi'ch in turn moves arm 8'2 to: theright and causes detent 8|, engaging with a tooth, as 80', of thetoothed wheel 19 to rotate that wheel in a clock wise direction, asviewed in Fig. '3. This move ment causes shaft 18 to move in a;clockwise di section, as viewed in t ig. c, and so causes the belt 15 t0move the disc 56 in a Clock-Wise dlr tion, so that if the shaft 46, asviewed in Fig. '8, 1S lbtatlng m "it counter clockwise dllectibi'l, thllthe breaking of the circint by the cbfltal'ts 68 and 69 will occurearlier in the rotation of the shaft.

In order to prevent too free movement of disc sit-a spring member 204filay have one ehd hearing thereagainst and the other end fastened tothe casing 25.

The shaft l8, as-most clearly shown in Fig; 7, is supported by a bearingSI and extends to the left, as viewed in Fig. '7, through an orifice 92at the end of the casing and has, on the outside of the casing, a fingerpiece 93 mounted thereon. By rotating this finger piece, the contactsdisc 56 may be adjusted without an energization of the solenoid 86. Inorder to allow a clockwise or counter clock-Wise rotation of shaft 18by'linger piece 93, even if the detent '81 engag ing in a tooth an ofthe wheel 19 would act to prevent it, adjustment wheel 19 is rotativelymounted on shaft 18 so that drive shaft 18 may be rotated independentlyof wheel I9. In order to drive shaft 18 by wheel 19 a member 94 ispositioned on the shaft and between 94 and the wheel 19 is adisc spring'95 furnishing sufiici'ent friction, so that when wheel 19 is turned,the shaft '18 will turn. Shaft 18 nevertheless may be turned by hand byfinger piece 93,even if in'ov'd in a direction which brings a tooth ofthe wheel 19 intoengagement with the detent 8|.

it shouldbe noted that in describing the par ti'cular type of circuitcontroller used, selection has been made of a controller in which itscon tac'ts, such as 68 and 69 are normally closed. Of course, it isunderstood that it is not intended to exclude a construction in whichthese contacts can be used as normally open contacts to be closed by thecontact of cam 51 with the member 14. In my preferred construction, itis best to use the normally closed'type of contacts at 6B and 69. Forthis reason, it is best to provide a means, whereby current will notpass through these abutted contacts except when desired. For thispurposeI rovide a hand operated switch.

In Fig. 9 there is shown a depression 9'6 at the end 16 of the casing.This depression communicates with a through bore 9''! in which ispos'itioned a button 98 formed with a shoulder 99 which abuts a rim I00attached, as by screws. as ['61, to the casing. Theinner end of thebuttori i8 abuts an insulated strip I02 which is fastenedalt-the end I03only, in any suitable or appropriate manner, as by the screw I114. Thescrew M also holds the metallic spring electrical conductin member I05which is providedwith a hump Hit. By pressing'button 98, member 1115at'the hum 1'06 contacts metallic electrical conductingsprlng l0? andmakes contact therewith. spring IUf, as best shown in; Fig. 6, isattached to disc 56 by screw Hi8 which passes through the disc 5'6 andapears', as shown in Fig. 8, bearing the nut I09 and holding the end ofconductor Ht. In order to suitably insulate electrical circuits, aninsulation strip Ill ispos'itioned between spring l0"! and the ballbearing 53 at the end of shaft 46. The spring H15, shown in Fig. 9, isalso shown n Fig; 6, but it is shown'in dash lines as it is in front ofthe plane of sectionupon' which Figfiistaken.

Thespring lll5'may be contacted by H" by'pressure on lla 'but it mayalso be moved permanently ihto contact with contact strip 101by'manipulating pin I09. This pin I09 when moved from the full lineposition to the dotted line position, as shown in Fig. 4, moves thebutton 98 inwardly, or to the left, as shown in Fig. 9, because the pinI09 is cammed to move button 98 by a projection When pin I09 restsbetween 0' and III, and partly on each, it holds spring I constantly incontact with I01.

The object of the circuit closing arrangement including the spring I05is to be able to have the circuit through contacts 68 and 69 usuallyopen but sometimes it is desired to have those contacts in a closedcircuit. This may be done momentarily or for a very short time bypressure upon button 98. If it is desired to have the circuit completedfor some considerable time or continuously, this may be done by movingpin I09 to a position between projections H0 and III and bearing oneach.

The end 36 of the casing 25 is provided with a sight opening H2 and azero mark I I3. Within the casing there is attached to the contactscarrying disc 56 a graduated scale II4, attached to the disc 56 in anysuitable or appropriate manner, as by means of tabs H5 and H6 and screwsII 1 and I I8. This graduated scale may be used in various ways toobtain various sorts of information all depending upon the fact that thescale rotates in unison with disc 56, and the fact that cam 51 causes aseparation of contacts 68 and 69 at a particular reading of the scalereferred to line II3, as zero. If disc 56 is adjusted so that cam 51breaks contacts 68 and 69 at different angular positions the difierencein angular degrees between the first position of breaking and the secondposition may be indicated by the difierence in reading on the scale II4with reference tothe zero line II3. In short, applicant provides a meansby which the circuit change may take place at difierent angularpositions in reference to a given plane through the axis of a rotatingbody and he provides means, whereby a variation of the position in whichthe circuit changes may be determined in angular degrees.

In Fig, 10, the side of vibrometer I6 is shown in elevation. A toothedfinger wheel I I5 is shown rotatable upon stub shafts as I I6. Theteeth, as best shown in Fig. 12, engage a ball I I1, it being understoodthat a cylinder would be equally appropriate, bearing against insulatingleaf IIIl secured at one end, that is, end II9. When the finger wheel II5 is moved to depress ball II1 successively by the teeth thereon, theinsulation H8 is depressed and along with it the metallic spring I20 tocause its point I2I to touch metallic point I22 positioned on metallicspring I23. Springs I20 and I23 may be included in any desired circuit.In the particular case considered, they are included in the circuitwhich includes the solenoid 86 and thiscircuit, as will be hereinaftermore fully described, when completed, by means of finger wheel 5', onetooth at a time, completes a circuit for solenoid 86 so it-is energizedmomentarily and deenergized, so that a step by step movement of wheel 19is caused.

The manner in which the various'devices shown in Fig. 1 areinterconnected electrically. is shown by the wiring diagram,'Fig. 14. Inthis diagram, I6 indicates the vibrometen, 23 indicates the hand neonlamp. 2| indicates therotary body driven circuit controller. 20designates the junction box.

In the diagram, Fig. 14, the several pieces of apparatus are shownelectrically connected by cables. These cables consist of two or morewires and all of them together constitute the cables of which one isdesignated I24, another I25, and another I26.

With all parts in position, as shown in Fig. 1, the circuits will be asshown in Fig. 14. Under such conditions, the first action is to closethe circuit between I05 and I01. This causes a flow of current from thebattery I21 in a circuit, as follows: positive terminal of the batteryI21, wires I28 and I29, switch arm I30, wire I3I, primary I32 of thetransformer, other terminal of the primary to wire I33, wire I34,connecting receptacle I35, wire I36, connecting receptacle I31, wireI38, switch arm I05, contact strip I01, wire I39, spring .1I, contactarm 61, contact point 68, contact point 69, wire I40, connectingreceptacle I4I, wire I42, connecting receptacle I43, and wires I44, I45,and I46 to the negative terminal of the battery I21. Current flowing inthe above traced path causes an energization of the primary I32 of thetransformer and so causes an induced current in the secondaries I41 andI 48, upon a make or break of the primary circuit.

Itwill be noticed that a condenser I 62, as is usual, is connectedacross the receptacles I43 and I35, which is in effect across thecontacts 68 and 69.

With secondaries I41 and I48 energized, a current then flows, asfollows: one terminal I49 of the secondary I 48, wire I50, connectingreceptacle I5I, wire I52, connecting receptacle I53, wire I54, hand neonlamp 23, wire I55, connecting receptacle I 56, wire I51, connectingrecep tacle I58, wires I59 and I46, battery I21, wires I28 and I29,switch arm I30, wire I3I, primary I32, wire I65, secondary I41, andwires I66, I61, and I68 to the other terminal of secondary I48. Currentwill flow in secondaries I41 and I48 only at the moment that contacts 68and 69 separate, but when it does flow, it energizes lamp 23 so that theparticular numeral on the end of rotating body I3 in the horizontalplane, that is, at arrow 25 may be ascertained.

At the same time that the neon lamp 23 is energized, the neon lamp I69in the vibrometer I 6 is energized by a circuit in which current fiows,as follows: terminal I66 of secondary I41, wire I10, connectingreceptacle I1I, wire I12, connecting receptacle I13, wire I14, neon lampI69, other terminal of neon lamp I69 wires I15, and 20I connectingreceptacle I16, wire I11, connecing receptacle I18, wire I19, resistanceI80, wires I45 and I46. battery I21, wires 528 and I29. switch arm I30,wire I3I, primary I22, wire I65, and secondary I41. Due to the currentflow in the above traced circuit, the neon lamp I69 is energized andcreates a band, I9, on the vibrorneter I6. This band may not be in theextreme right-hand position, as shown in Fig. 1, and, consequently, itis necessary to bring it to the extreme right-hand position, This isdone by energizing solenoid 86. The means for energizing solenoid 86includes the hand operated switch 24, as shown in Fig. 1, on vibrometerI6. When the toothed wheel I I5, of Figs. 10 to 13 inclusive, is rotatedtooth by tooth contacts I2I and I22 are brought together upon thepassage of a tooth by ball M1 as shown in Fig. 12, and then areseparated when the ball II'I engages between two teeth. In Fig. 14, whenthe contacts I2I and I22 are brought together, as by movement of toothedwheel H5, a circuit is formed, as follows: positive terminal of batteryI21, wires I28 and I, connecting receptacle I8I, wire I82, connectingreceptacle I83, wires I84 and I85. contact point I2I, contact point I22,wire I86, connecting receptacle I81, wire I88, connecting receptacleI89, wire I90, connecting receptacle I9I, wire I92, connectingreceptacle I93, wire I94, solenoid 86, the other side of solenoid 86 toground I95, ground I96, wire I91, connecting receptacle -I4I, wire I42,connecting receptacle I43, wires I44, I45, and I 46 to the other side ofthe battery I21. Current flowing in the above traced path energizessolenoid 86 and causes the toothed wheel 19 to be moved in a clock-Wisedirection, as viewed in Fig. 3. As the finger wheel H5 is moved tooth bytooth, the toothed wheel 19 is actuated and the angular position, withreference to a given plane through the longitudinal axis of the rotatingbody, at which the contacts 88 and 69 separate, is changed. In theinstant case, the adjustment will continue until the neon band reachesthe extreme right-hand position, as shown in Fig. 1. Under suchcondition-s the contacts will separate at the very instant when thehigh-spot of the rotating body I3 is in the horizontal plane passingthrough the longitudinal axis of the shaft I4, at which time, theamplitude of vibration operating on point I1 would be a maximum and atthe same time the neon lamp 23 will indicate the numeral at the end ofthe rotating body I3, which is seen at that time to be numeral 6.

At the same time that the neon lamps are being energized, the lamp forgiving a white line, to indicate amplitude of vibration on scale I8,would also be energized by a circuit, as follows: positive terminal ofbattery I21, wires I28 and I80, connecting receptacle IBI, wire I82,connecting receptacle I83, wires I84 and I98, filament lamp I99, wires200 and 20I, connecting receptacle I16, wire I11, connecting receptacleI18, wire I19,

resistance I80, and Wires I and I46 to the other terminal of the batteryI21.

In some cases it is desirable and even necessary to use a primary on thetransformer having more turns therein. In such cases, the switch I30instead of connecting wire I3I, would be moved to connect with wire 202and so to the terminal 203 of the primary I32, so that then the primarycircuit would include a larger number of layers than the primaryconnected into the circuit including wire I 3|. This is exceptionallyuseful in connection with relatively low speed rotary bodies.

In Fig. 14, the pivoted mirror 202 operated by lever 203 from point I1throws the light of the lamps I69 and I99 on any suitable receivingsurface as fully pointed out in the patent hereinbefore referred to.

Although the rotary body circuit controller has been described asparticularly useful in connection with a vibrometer. it is to beunderstood that it is of general application and for a stroboscopic viewsolely of the rotary body, for instance. the vibrometer may be omitted.The switching means shown herein attached to the vibrometer, has beenattached thereto for greater convenience in use. The vibrometersupporting the switching means for stepping the disc 56 about may, whenthe apparatus is used merely as a stroboscopic device, be consideredmerely a convenient support for the switching device, but not the onlypossible support.

Although I have particularly described my invention and a particularphysical embodiment of apparatus, nevertheless, I desire to have itunderstood, that the form selected is merely illustrative and does notexhaust the possible physical embodiments of the idea of meansunderlying my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. In a stroboscopic circuit controller, in combination: a shaft; meansfor rotating the shaft; a cam on the shaft; a pair of abuttablecontacts; a disc mounted concentrically with the shaft; an oscillatablemember mounted on the disc, said oscillatable member supporting the saidcontacts; means for fastening the oscillatable member in an oscillatedposition: means pivoting one of the contacts so that it may be movedrelatively to the other contact and including a part adapted tocooperate with said cam; an electro-magnet including an armature; arotatable toothed wheel; means associated with the armature whereby thetoothed wheel is rotated by successive energizations of theelectro-magnet; means for causing successive energizations ofelectromagnet; means including a friction clutch, connecting the toothedwheel and the disc whereby the disc is rotated about the shaft andwhereby the angular position about the shaft of the cooperation of thecam and one of the contacts is progressively varied; and a dischargelamp controlled by the said contacts.

2. In a stroboscopic circuit controller, in combination: a shaft; meansfor rotating the shaft; a cam on the shaft; a pair of abuttablecontacts, a disc mounted concentrically with the shaft; an oscillatablemember mounted on the disc, said oscillatable member supporting the saidcontacts; means for fastening the oscillatable member in an oscillatedposition; means pivoting one of the contacts so that it may be movedrelatively to the other contact and including a part adapted tocooperate with said cam; an electro-magnet including an armature; arotatable toothed wheel; means associated with the armature whereby thetoothed wheel is rotated by successive energizations of theelectro-magnet; means for causing successive energizations ofelectromagnet; means, including a friction clutch connecting the toothedwheel and the disc whereby the disc is rotated about the shaft andwhereby the angular position about the shaft of the cooperation of thecam and one of the contacts is progressively varied; a discharge lampcontrolled by the said contacts: a graduated member attached to the saiddisc and a zero mark to indicate the angular displacement of the discfrom a known position.

PETER DAVEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,087,454 McMurtry Feb. 17, 19141,882.720 Arthur Oct. 18, 1932 1,216,745 Starker Feb. 20, 1917 1,949,603Davey Mar. 6, 1934 1,392,028 Torbet Sept. 27, 1921 1,639,444 Terry Aug,16, 1927 2,050,073 Thearle Aug. 4, 1936 2,314,287 Pope Mar. 16, 19432,127,605 Kucher Aug. 23, 1938 2,000,153 Watson May 7, 1935 1,271,748Nelson July 9, 1918 1,858,985 Davey May 17, 1932 2,004,270 Davey June11, 1935 2,191,087 Spengler Feb. 20, 1940 2,043,845 Thearle June 9, 1936

